The target surface of the CMOS circuit board is a key part of the star sensor structure， and its assembly attitude affects the accuracy of the defocus distance， and then affects the imaging performance of the star sensor. Therefore， the assembly and adjustment of the target surface is an important link to ensure the imaging quality of the star sensor. At present， the assembly and adjustment of the target surface is mainly completed by manual assembly and adjustment， and there are some problems， such as low precision， poor product consistency， long cycle and so on， resulting in low rate of quality products. For this reason， an automatic assembly and adjustment equipment for the target surface of CMOS circuit board of star sensor was developed. The non-contact measurement mode was adopted， and the measurement module and fretting platform were integrated to complete the relative position and attitude measurement between the CMOS target surface and the datum surface， which solved the problem of high precision measurement in the narrow space caused by the special structure of the star sensor. The design adjustment mechanism could flip the parts at any angle and eliminate the influence of the complex layout of the system structure caused by the inconsistency between the measuring direction and the assembly direction. Finally， the accuracy of the measurement system was analyzed， and the algorithm of adjusting gasket grinding amount was developed by using local enumeration method to solve the problem of under-determination of multi-gasket grinding quantity from a single known quantity of plane attitude. The experimental results show that the system can realize the function of automatic assembly and adjustment of the target surface， and measurement repeatability of the system is 0.8′， which meets the technical requirements.